Magnetic latch

ABSTRACT

A magnetic latch comprises a pair of magnets in mutually repelling position so that one of them is urged into a latching position, and a third magnet which when brought close to the latching magnet overcomes the repulsion and withdraws the latching magnet, and when remote from the latching magnet permits the latching magnet to resume latching position.

United States Patent 1 Berducone 11 3,744,833 1 July 10, 1973 1 1MAGNETIC LATCH [76] Inventor: Dominique Berducone, 18 Rue de la Vega,Paris, France [22] Filed: Apr. 14, 1971 [21] Appl. No.: 133,796

[30] Foreign Application Priority Data Apr. 15, 1970 France 7013539 [52]US. Cl 292/25l.5, 70/276 [51] Int. Cl. E05c 19/16 [58] Field of Search292/25l.5, 144, 201

[56] References Cited UNITED STATES PATENTS 2,809,062 10/1957 Mainhardt292/144 2,219,186 10/1940 Homfeck 292/144 3,095,723 7/1963 McKnight etal. 292/201 X 2,468,969 5/1949 Galey 292/ 144 3,069,193 12/1962 Kirk292/144 FOREIGN PATENTS OR APPLICATIONS 435,375 5/1948 ltaly 292/144Primary Examiner-Richard E. Moore Attorney-lrvin S. Thompson [57ABSTRACT A magnetic latch comprises a pair of magnets in mutuallyrepelling position so that one of them is urged into a latchingposition, and a third magnet which when brought close to the latchingmagnet overcomes the repulsion and withdraws the latching magnet, andwhen remote from the latching magnet permits the latching magnet toresume latching position.

1 Claim, 6 Drawing Figures Pmamio 3.744.833

Fig-4 Fig-5 Fig-6 INVENTQR DOM/N/OUE .5ERDUONE avyw- 7 60 ATTORNEXSMAGNETIC LATCH The present invention relates to magnetic latches.

It is an object of the present invention to provide a magnetic latchwhich utilizes only magnetic attraction and repulsion and hence is freefrom the difficulties which ordinarily attend the use of magneticlatches.

Another object of the present invention is the provision of a magneticlatch which will be relatively simple and inexpensive to manufacture,easy to operate, and rugged and durable in use.

Other objects, features and advantages of the present invention willbecome apparent from a consideration of the following description, takenin connection with the accompanying drawing, in which:

FIG. 1 is a view in cross section of a magnetic latch not according tothe present invention but showing certain structure known in the priorart;

FIG. 2 is a fragmentary cross sectional view showing a magnetic latchactuated by the repulsion of a pair of magnets;

FIG. 3 is a view similar to FIG. 2 but showing a magnetic latchaccording to the present invention in the withdrawn position;

FIG. 4 is a view similar to FIG. 3 but showing the latch in extendedposition, to retain the cover of a container;

FIG. 5 is a view similar to FIG. 4 but showing the parts in the FIG. 3position to permit removal of the cover; and

FIG. 6 is a fragmentary top plan view of a portion of a latch structureaccording to the invention.

Referring now to the drawing in greater detail, and first to FIG. 1thereof, there is shown a container B with a recess D in the sidethereof in which is disposed a coil compression spring R that bearsagainst the underside of a magnet A having a north pole N and a southpole S to urge the magnet into latching position.

FIG. 2 also shows a fragmentary view of a box B in cross section, havinga cavity D therein in which is disposed a permanent magnet A having anorth pole N and a south pole S, and also a further magnet A smaller andweaker than the magnet A and disposed on the inside of the container B.The poles of the magnets A and A are so related that the fixed magnet Aurges the movable magnet A into the latching position shown in FIG. 2.

FIG. 3 is a view similar to FIG. 2, but showing a third magnet A",larger and stronger than magnet A, whose poles are arranged inattractive relationship to magnet A so that in the FIG. 3 position, whenmagnet A" is relatively close to the magnet A, then the magnet A isdrawn down into retracted position against the repulsive force of magnetA.

FIG. 4 shows the same structure as in FIG. 3, but with the permanentmagnet A relatively remote from the magnet A, so that the magnet A issufficiently strong to repel the magnet A into the latching positionshown in FIG. 4 in which magnet A enters a recess in the underside of acover E to latch the cover in place.

FIG. 5 shows the same structure as in FIG. 4, but with magnet A" in theFIG. 3 position and the magnet A retracted to unlatched position so thatthe magnet A is withdrawn from the recess F in the underside of cover Eand cover E can be retracted.

FIG. 6 shows in plan the structure of FIG. 2.

Of course, appropriate housings and mountings will be provided, formounting the parts relative to each other, and particularly for mountingmagnet A" for ready manipulation toward and away from the container soas respectively to retract and to extend the latch of the presentinvention which is the permanent magnet A. Such housings and connectionsare not shown in the drawing, it being understood that they can take anyconventional form.

In view of the foregoing disclosure, therefore, it will be evident thatthe initially recited objects of the present invention have beenachieved.

Although the present invention has been described and illustrated inconnection with a preferred embodiment, it is to be understood thatmodifications and variations may be resorted to without departing fromthe spirit of the invention, as those skilled in this art will readilyunderstand. Such modifications and variations are considered to bewithin the purview and scope of the present invention as defined by theappended claims.

Having thus described my invention, I claim:

1. A container having a magnetic latch comprising a pair of permanentmagnets arranged to repel each other, one of said magnets being mountedfor movement on and relative to the container between extended andretracted positions, and a third permanent magnet movable toward andaway from said one magnet selectively to overcome the repulsion of saidpair of magnets thereby to draw said one magnet to said retractedposition, to other of said pair of magnets being fixedly mounted on theinside of said container, said one magnet being mounted for movementparallel to the poles of said fixed magnet, said third magnet beingmovable in a direction transverse to the path of movement of said onemagnet.

III l

1. A container having a magnetic latch comprising a pair of permanentmagnets arranged to repel each other, one of said magnets being mountedfor movement on and relative to the container between extended andretracted positions, and a third permanent magnet movable toward andaway from said one magnet selectively to overcome the repulsion of saidpair of magnets thereby to draw said one magnet to said retractedposition, the other of said pair of magnets being fixedly mounted on theinside of said container, said one magnet being mounted for movementparallel to the poles of said fixed magnet, said third magnet beingmovable in a direction transverse to the path of movement of said onemagnet.